diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index a0bb13825109..85fc0e6f0f7f 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -738,7 +738,8 @@ __FORTIFY_INLINE void *kmemdup(const void * const POS0 p, size_t size, gfp_t gfp
 	if (__compiletime_lessthan(p_size, size))
 		__read_overflow();
 	if (p_size < size)
-		fortify_panic(FORTIFY_FUNC_kmemdup, FORTIFY_READ, p_size, size, NULL);
+		fortify_panic(FORTIFY_FUNC_kmemdup, FORTIFY_READ, p_size, size,
+			      __real_kmemdup(p, 0, gfp));
 	return __real_kmemdup(p, size, gfp);
 }
 
diff --git a/lib/fortify_kunit.c b/lib/fortify_kunit.c
index ef3e4c68b759..306522fd0aa2 100644
--- a/lib/fortify_kunit.c
+++ b/lib/fortify_kunit.c
@@ -1002,19 +1002,19 @@ static void fortify_test_kmemdup(struct kunit *test)
 
 	/* Out of bounds by 1 byte. */
 	copy = kmemdup(src, len + 1, GFP_KERNEL);
-	KUNIT_EXPECT_NULL(test, copy);
+	KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR);
 	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1);
 	kfree(copy);
 
 	/* Way out of bounds. */
 	copy = kmemdup(src, len * 2, GFP_KERNEL);
-	KUNIT_EXPECT_NULL(test, copy);
+	KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR);
 	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
 	kfree(copy);
 
 	/* Starting offset causing out of bounds. */
 	copy = kmemdup(src + 1, len, GFP_KERNEL);
-	KUNIT_EXPECT_NULL(test, copy);
+	KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR);
 	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 3);
 	kfree(copy);
 }